In a common channel signaling network, such as an SS7 network, call signaling messages are used to set up and tear down calls between end users and to communicate with databases. These call signaling messages are sent over signaling links to a signaling node that routes the call signaling messages to the appropriate destination. The signaling links can be SS7 signaling links, IP signaling links, or other signaling links suitable for carrying call signaling messages. The node that conventionally handles such signaling links is referred to as a single transfer point or a signaling gateway.
One problem with conventional signal transfer points or signaling gateways occurs when one of the signaling links fails. When a signaling link fails, messages directed to that link are buffered. The signal transfer point or signaling gateway determines an alternate route to the destination and sends the buffered messages over an alternate outgoing signaling link (if available) that has not failed. Because SS7 signaling links are typically underutilized, i.e., only about 40% of total capacity is typically used, the message transfer rate of the outgoing signaling links can be increased relative to the message transfer rate of the incoming signaling links until all of the messages that were buffered for the failed signaling link have been transmitted. Once the signaling gateway transmits all of the buffered messages, the capacity of the outgoing signaling link can be decreased back to its normal level.
The process described above for responding to a signaling link failure works well only when the incoming and outgoing signaling links are low speed signaling links, i.e., capable of processing no more than about 300 messages per second. If the incoming signaling link is a high speed signaling link, i.e., capable of processing 2000 or more messages per second, the buffer used to store messages when the outgoing signaling link fails can quickly be overrun. In addition, even if the buffer is not overrun, it may take a long period of time for the outbound signaling link to deplete the messages stored in the buffer when another signaling link fails. Thus, there exists a need for novel methods and systems for performing flow control between incoming and outgoing signaling links in a signaling point when one or more of the signaling links fails.